1. Field of the Invention
The invention relates to access floor systems of the modular type which are used elevated to provide space for conduits or cables such as are used for computers or other electronic equipment. The invention is concerned with the panel construction for such floor systems and in particular with the edge construction of such panels.
2. Description of the Prior Art
Tate U.S. Pat. No. 3,396,501 shows an example of a panel construction in such systems wherein a flat upper metal load receiving panel and a lower steel panel have their marginal edges in close contact to form a peripheral flange on the panel. Channel shaped edge strips are slipped over these margins, and a wear surface covering layer on the upper steel panel is flush with the upper flange of the edge strip. In order to secure the edge strip to the panel flange, it is known to utilize cement, as described in the aforementioned patent. It is also known to form longitudinal serrations on the inside flange surfaces of the channel shaped edge strip in an attempt to grip the composite marginal panel flange on both top and bottom.
However, these prior methods and constructions for securing the edge strip in position have been found to be less than satisfactory. In use, access floor panels are periodically removed and replaced in order to service the equipment underneath. This often involves strong impacts on the edge strips, especially when the panels are being replaced at which time they may be kicked or struck by a tool. The result is a pervasive problem of edge strip loosening or peeling off. Once the edges become deformed, loose or removed, the panel is subject to water damage especially if water leaks underneath the outer margins of the wear surface covering layer, which then in turn could become partially or completely dislodged.
A solution which has been proposed for this problem is to place an extra part on the outside of the panel which surrounds the edge strip to hold it in place. This however is an expensive construction and it is difficult to maintain proper dimensional control which is needed for installation.
Another difficulty resulting from loose or missing edge strips is that it becomes difficult to properly install a long series of panels. Proper installation requires that the panel fit very closely to prevent "growing" in long stretches; otherwise, difficulty will be encountered when trying to fit the panels between two opposite walls in a large room.